RESUMEN
The in vivo and in vitro response of Plasmodium falciparum to a single oral dose of mefloquine (25 mg/kg body weight (M25) or 15 mg/kg (M15] was studied in children under 5 years of age in Malawi. Of the children who received mefloquine, 35% vomited at least once, and 10% did not tolerate the drug because of vomiting. The therapy failure rates for the M25 group on day 7, 14, and 28 were 15%, 18%, and 42%, respectively, and these did not differ significantly from those for the M15 group (4%, 18%, and 59%). In contrast, 34 in vitro microtests (17 per group) showed schizont inhibition at less than or equal to 32 pmol mefloquine per test well. On day 7, the concentration of mefloquine in samples of blood was significantly lower in both the M25 and M15 groups for children who were parasitaemic on day 7 than in samples from those who were aparasitaemic. A positive blood smear on day 7 was strongly associated with a mefloquine concentration of less than 500 ng/ml blood on day 2 or day 7 (P less than 0.0003). Vomiting was associated with a low mefloquine concentration on day 2 but not day 7. These results suggest that mefloquine is effective against P. falciparum in Malawi but that for young children the therapy appears to be complicated by frequent vomiting
Asunto(s)
Farmacorresistencia Microbiana , Lactante , Recién Nacido , Malaria/tratamiento farmacológico , Malaui , Mefloquina/administración & dosificación , Mefloquina/uso terapéuticoRESUMEN
An American Peace Corps volunteer contracted chloroquine-resistant Plasmodium falciparum malaria while serving in Malawi and taking regular chloroquine prophylaxis. Resistance was confirmed by in vitro testing of his parasites for chloroquine and pyrimethamine. The possibility of Fansidar-resistant falciparum malaria was also suggested in this case. American expatriates residing in or traveling to Malawi are advised to either take both chloroquine and Fansidar; or alternatively amodiaquine or doxycycline alone. Any breakthrough of slide-proven falciparum malaria in these individuals should be seriously suspected to be chloroquine- and Fansidar-resistant malaria; and should be treated with quinine and tetracycline